The present invention relates to an apparatus for cooling components, e.g., semiconductors. More specifically, the invention relates to a cooling assembly that provides redundant cooling for high powered microprocessors.
Because certain systems, e.g., servers, must minimize downtime, redundant features are often built into them. Redundancy enables the system to continue running, even when a defective component must be replaced. Such a system cannot continue to operate if the microprocessor cooling system fails. Consequently, such systems frequently rely upon redundant components to perform that cooling function.
Conventionally, heat is removed from microprocessors by placing a heat sink next to them, and forcing fan driven air across the heat sink. When redundant fans are included in a server to cool the microprocessor, or microprocessors, a first fan may drive air over the heat sink while a second fan draws air from the heat sink. If one fan fails, the remaining fan""s speed may be increased to compensate for that failure, enabling the system to continue running until the defective fan can be replaced.
A problem may arise when one fan""s failure serves to obstruct airflow that the other fan generates, such as may occur in systems that employ a series redundant cooling scheme. Consider, for example, the system 100 illustrated in FIG. 1a. System 100 includes chassis 120, which encloses duct 102. In normal operation, first fan 101 (i.e., the leading fan, which is positioned at first end 110 of duct 102xe2x80x94the inlet section of duct 102) forces air through duct 102 and over the device to be cooled, e.g., microprocessor 103. Second fan 104 (i.e., the trailing fan, which is positioned at second end 111 of duct 102xe2x80x94the exhaust section of duct 102) draws air through duct 102 from microprocessor 103. Airflow direction through duct 102, and over microprocessor 103, is indicated by arrows 112 and 113.
As shown in FIG. 1b, if first fan 101 fails, second fan 104 must carry the entire cooling load. In this particular design, however, defective first fan 101 obstructs airflow through duct 102, which may prevent second fan 104 from providing adequate cooling for microprocessor 103xe2x80x94even if second fan 104 significantly increases its speed. Similarly, as shown in FIG. 1c, if second fan 104 fails, it obstructs airflow through duct 102, which may prevent first fan 101 from providing adequate cooling for microprocessor 103xe2x80x94even if first fan 104 significantly increases its speed.
Accordingly, there is a need for an improved cooling assembly that provides redundant cooling. There is a need for such a system that ensures that the failure of one fan does not obstruct airflow generated by a second fan. The cooling assembly of the present invention provides such a system.